Merge tag 'efi-2020-10-rc1' of https://gitlab.denx.de/u-boot/custodians/u-boot-efi into next

Pull request for UEFI sub-system for efi-2020-10-rc1

This series comprises error corrections for the UEFI subsystem:

* correct consideration of timestamps for variable authentication
* correct collection of data regions for code authentication
* correct unit tests to test loading dbx
* enable FAT_WRITE as required by the UEFI spec

The boot manager uses log functions instead of printf() and debug().

The UEFI intialization state is exported.